On my computer, AMD X64 double core, Win XP32 SP3 , the best IvanHoe was T52D. I matched it against T52E at 400 msec + 40 msec time control, 16,034 games (I got bored testing more)

http://img801.imageshack.us/img801/2888/blitz18.jpg

They are virtually equal within +/-4 Elo points interval with ...